Technical description

Scope : page

Decision level :
semidecidable

Algorithm

Selection

Set1 :

All the <a> tags with a href attribute, with children (a[href]:has(\*) )

Set2 :

All the elements of Set1 without own text and with only one child of type img or object (img , object[type\^=image], object[data\^=data:image], object[data$=png], object[data$=jpeg], object[data$=jpg],object[data$=bmp], object[data$=gif]) (assuming the definition of an image link in AccessiWeb 2.2)

Process

Test1

For each element of Set2, we check whether the link content (content of the alt attribute of the child tag) doesn't belong to the text link blacklist.

For each element returning false in Test1, raise a MessageA, raise a MessageB instead

Test2

For each element of Set2, we check whether the link content (content of the alt attribute of the child tag) doesn't only contain non alphanumeric characters

For each element returning false in Test2, raise a MessageA, raise a MessageB instead

MessageA : Unexplicit Link

code : UnexplicitLink

status: Failed

parameter : link text, title attribute, snippet

present in source : yes

MessageB : Check link without context pertinence

code : CheckLinkWithoutContextPertinence

status: Need More Info

parameter : link text, title attribute, snippet

present in source : yes

Analysis

NA :

Set1 is empty (the page has no image links)

Failed :

Test1 OR Test2 returns false for at least one element (At least one element of the Set2 has a child tag with an alt attribute content which is blacklisted or that only contains non alphanumerical
characters)

NMI :

In all other cases

Notes

We assume here that the image links with only one child of type img or object